world cancer report - iarc

LYMPHOMA
SUMMARY
> Malignant lymphomas are classified as
either Hodgkin disease or non-Hodgkin
lymphoma.
> Hodgkin disease afflicts mainly children
and the elderly in developing countries
and young adults in more developed
countries; 62,000 new cases are diagnosed
annually.
> The incidence of malignant non-Hodgkin
lymphomas is increasing worldwide;
more than 280,000 new cases occur
annually, predominantly in more developed
countries.
> Burkitt lymphoma is a subtype of malignant
B-cell lymphoma common in Africa
in regions with endemic malaria. B-cell
lymphomas may also be caused by
immunosuppression. Both are commonly
associated with the Epstein-Barr virus.
> Advances in chemotherapy have led to a
five-year survival rate for Hodgkin disease
of more than 70% and that for non-
Hodgkin lymphomas has increased to
60-70%.
Definition
The term lymphoma covers a heterogeneous
group of neoplasms of lymphoid tissue.
Traditionally, lymphomas are categorized
as either Hodgkin disease or non-
Hodgkin lymphoma, these distinct entities
having different patterns of behaviour and
response to treatment. Within each of
these two entities there is a range of
diverse subtypes.
Epidemiology
Non-Hodgkin lymphomas are a very varied
group of neoplasms. Excluding the types
that generally manifest as leukaemias
rather than single or multiple aggregates
of cells, there are around 287,000 cases
of non-Hodgkin lymphoma in the world
< 3.7
< 5.0
Fig. 5.97 Global incidence of non-Hodgkin lymphoma in men. The disease is most common in developed
countries, although there are areas of moderate to high incidence in some Middle-Eastern countries and
in parts of sub-Saharan Africa.
per year. More males than females are
affected (17.1 cases per 100,000 males
compared to 11.2 cases per 100,000
females in the USA) and incidence
increases with age. Geographically, non-
Hodgkin lymphoma is most common in
developed countries (52% of the world
total cases, and the seventh most common
cancer in more developed countries),
although in the developing world there are
areas of moderate to high incidence in
some Middle-Eastern countries (Saudi
Arabia, Israel) and in parts of sub-Saharan
Africa (Fig. 5.97). The latter is due to the
high incidence of Burkitt lymphoma, an
aggressive subtype of non-Hodgkin
lymphoma, particularly in children in tropical
Africa. Papua New Guinea also has
high rates of Burkitt lymphoma.
The incidence rates of non-Hodgkin lymphoma
have risen dramatically in the last
20 years, particularly in developed countries,
including Western Europe, North
America and Australia (Fig. 5.99). This
may in part reflect better diagnosis, or
< 6.8
< 8.9
Age-standardized incidence/100,000 population
< 16.1
changing classification systems. However,
these considerations together do not
account for the extent of increase.
Likewise, the fact that non-Hodgkin lymphoma
is a complication of AIDS (occurring
in up to 5-10% of AIDS cases in developed
countries) does not completely
account for the increasing trend. In contrast
to incidence, mortality rates have, in
general, been declining as a consequence
of improvement in therapy.
Hodgkin disease comprises about 23% of
malignant lymphomas worldwide (about
62,000 annual cases). There is a male predominance
(sex ratio 1.6:1). In developing
countries, Hodgkin disease (predominantly
the mixed cellularity subtype) occurs
mainly in children and in the elderly, while
in developed countries there is a peak in
young adults (mainly the nodular sclerosing
subtype). The disease is rare in
Eastern and South-Eastern Asian populations
at any age (Fig. 5.100). The pattern
of Hodgkin disease in black Americans
more closely resembles that of white
Lymphoma
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